<?php

//给图片添加水印
class Water{
    //开启水印
    private $watermark_on = '1';

    public $water_img = 'water.png';

    //压缩比
    public $pct = 80;

    //透明度
    public $quality = 80;

    public $text = 'Water';

    public $size = 12;

    public $color = '#000000';

    public $font = 'font.ttf';

    public function watermark( $img, $list,$out_img='',$water_img='',$text='' ){

        if(!$this->check($img) || !$this->watermark_on) return false;

        $water_img = $water_img ? $water_img : $this->water_img;
        //水印的开启状态
        $waterimg_on = $this->check($water_img) ? 1 : 0;
        //判断是否在原图上操作
        $out_img = $out_img ? $out_img : $img;
        //水印文字
        $text = $text ? $text : $this->text;


        $img_info = getimagesize($img);
        $img_w = $img_info[0];
        $img_h = $img_info[1];

        //判断水印图片的类型
        if( $waterimg_on ){
            $w_info = getimagesize($water_img);
            $w_w = $w_info[0];
            $w_h = $w_info[1];

            if ( $img_w < $w_w || $img_h < $w_h ) return false;
            switch ( $w_info[2] ){
                case 1:
                    $w_img = imagecreatefromgif($water_img);
                    break;
                case 2:
                    $w_img = imagecreatefromjpeg($water_img);
                    break;
                case 3:
                    $w_img = imagecreatefrompng($water_img);
                    break;
            }
        }else{
            if( empty($text) || strlen($this->color)!=7 ) return FALSE;
            $text_info = imagettfbbox($this->size, 0, $this->font, $text);
            $w_w = $text_info[2] - $text_info[6];
            $w_h = $text_info[3] - $text_info[7];
        }

        //建立原图资源
        switch ( $img_info[2] ){
            case IMAGETYPE_GIF:
                $res_img = imagecreatefromgif($img);
                break;
            case IMAGETYPE_JPEG:
                $res_img = imagecreatefromjpeg($img);
                break;
            case IMAGETYPE_PNG:
                $res_img = imagecreatefrompng($img);
                break;
        }
        //写入图片资源
        if( $waterimg_on ){
            foreach($list as $item){
                $x = floor((int)$item['x']);
                $y = floor((int)$item['y']);
                imagecopymerge($res_img, $w_img, $x, $y, 0, 0, $w_w, $w_h, $this->pct);
            }

        }else{
            $r = hexdec(substr($this->color, 1,2));
            $g = hexdec(substr($this->color, 3,2));
            $b = hexdec(substr($this->color, 5,2));
            $color = imagecolorallocate($res_img, $r, $g, $b);
            imagettftext($res_img, $this->size, 0, $x, $y, $color, $this->font, $text);
        }

        //生成图片类型
        switch ( $img_info[2] ){
            case IMAGETYPE_GIF:
                imagecreatefromgif($res_img,$out_img);
                break;
            case IMAGETYPE_JPEG:
                //imagecreatefromjpeg($res_img,$out_img);
                imagejpeg($res_img,$out_img);
                break;
            case IMAGETYPE_PNG:
                imagepng($res_img,$out_img);
                break;
        }
        if(isset($res_img)) imagedestroy ($res_img);
        if(isset($w_img))  imagedestroy($w_img);
        return true;
    }
    //验证图片是否存在
    private function check($img){
        $type = array('.jpg','.jpeg','.png','.gif');
        $img_type = strtolower(strrchr($img, '.'));
        return extension_loaded('gd') && file_exists($img) && in_array($img_type, $type);
    }
}